The present invention generally relates to a power supply system of supplying power to recording mediums housed in a storage apparatus, and in particular relates to a storage apparatus having a redundant power source and a disk subsystem including such a storage apparatus for improving the reliability in supplying power.
In recent years, pursuant to the development of information society, capacity of a disk subsystem including a magnetic disk apparatus as the storage apparatus is increasing year by year, and the number of loaded disks is also increasing. Meanwhile, in addition to the miniaturization and price reduction of apparatuses configuring the disk subsystem, higher reliability particularly in the steady supply of power or secure protection of data is being demanded. Accordingly, it is desirable that these apparatuses are configured as described below.
(1) In order to securely store data in hard disks, increase the number of hard disks to be loaded and housed in the disk subsystem, and increase the number of hard disks to be connected to the same motherboard and power source.
(2) In order to enable the normal operation of apparatuses configuring the disk subsystem even during a power source failure, connect the power source or power source cable for supplying power to the apparatuses in duplication or in a redundant configuration.(3) In order to realize non-disruptive maintenance, internally provide various detection report circuits in the apparatuses so as to detect and report a failure when such failure occurs in the power source of an operating apparatus.
As a magnetic disk apparatus including a system for improving the reliability of the power source, conventionally, a disk subsystem configured from a hard disk control logical unit and a disk unit has been proposed. This disk subsystem is configured to supply power to hard disks with two or more power sources mounted at each power source boundary (backboard). Each of the mounted power sources has sufficient output capacity for driving all hard disks so that the operation of the apparatuses will not be influenced even when one power source malfunctions and the output thereof is stopped. Further, each power source is configured so that two independent power source facilities can be connected so as to enable the operation even during a power source failure in a power source facility.
Further, when the output voltage is stopped due to a malfunction in the power source, each power source reports such malfunction of the power source to the power supply malfunction detection unit. Moreover, a power supply malfunction detection unit checks the voltage of the power source voltage to be provided to the hard disks, and such power supply malfunction detection unit detects a malfunction when the voltage falls below an operable voltage of the hard disks, and reports the malfunction of the power source to the hard disk control logical unit.
Further, there is a disk subsystem that is configured such that power can be separately supplied from the power source to the backboard based on the two or more power sources mounted in the apparatus, the hard disks have separate power sources, the power sources are input from two types of inputs on the backboard, and which adopts a power supply system of supplying power to the hard disks with a single output (refer to Japanese Patent Laid-Open Publication No. 2005-173941).